Golden times in the sun (with slideshow)
Posted on 5 December, 2014 by Connecting Country
One of the most threatened species to occur in the Mount Alexander shire and surrounds is the Golden Sun Moth (Synemon plana). This day-flying moth is considered to be ‘critically endangered’ on Federal legislation and ‘threatened‘ on state legislation. Its preferred habitat is native grasslands and grassy woodlands, but it is also occasionally seen flying over agricultural paddocks that still contain a good cover of native grasses – particularly wallaby grass (Austrodanthonia spp.).
This moth has an unusual life history – the full details of which are still being discovered. The adult female moth rarely, if ever, flies. Instead, she will mostly perch on the bare ground between grass tussocks on warm-to-hot days during the months of November to January, displaying her golden-coloured hind wings. The male moths (which have reddish-coloured hind wings) fly low over the sparse grassy vegetation, on the look-out for the female moths. After mating, it is believed that the female lays her eggs near the base of grass tussocks. The larvae then emerge from the eggs, and burrow down into the soil to feed; maybe on the roots of the grasses – or perhaps they feed on the mycorrhizal fungi that grows on the roots. After one or more years underground feeding, the larvae then pupate and emerge as adults moths to begin the cycle again. The adult moths have no mouthparts at all – and as such they only live for a maximum of 3-4 days after emerging, which is as long as their stored energy allows.
The adults moths will also often emerge en masse. It is suspected that this is part of a strategy to overwhelm predators such as spiders and robber flies. Certainly for these predators, the annual emergence of Golden Sun Moths represents a major feeding opportunity.
Adult Golden Sun Moths have been seen in Walmer, Barkers Creek and Taradale over the past couple of weeks by Connecting Country staff member Chris. Last season they were also seen near Castlemaine, Sandon and Sutton Grange.
A local landholder to the north of Castlemaine provided Connecting Country with the following incredible series of photos of adult moths that she took from her property last summer (2013-14).